(a) “Milk for manufacturing purposes” or “milk for pasteurization” shall be used in the preparation of “manufactured dairy products.”

(b) The “milk for manufacturing purposes” or “milk for pasteurization” used in the preparation of “manufactured dairy products” shall be pasteurized or otherwise treated as indicated by the “secretary” during the preparation of “manufactured dairy products.”

(c) Milk containers in which “milk for manufacturing purposes” or “milk for pasteurization” is received in milk plants for the preparation of “manufactured dairy products” shall be thoroughly cleansed and dried before returning to a dairy farm or milk plant.

(d) The rooms of buildings in which “manufactured dairy products” are exposed during and after preparation shall be properly lighted, ventilated, drained and clean and shall be used for no other purpose than to provide a place for cleansed containers and utensils and for the handling of “manufactured dairy products.”

(e) “Manufactured dairy products,” during and after preparation, and cleansed containers, utensils and equipment shall be protected from flies.

(f) Milk plants in which “manufactured dairy products” are prepared shall be provided with an adequate supply of steam or hot water for cleaning containers, utensils and equipment.

(g) Equipment with which “manufactured dairy products” come in contact shall be constructed in such a manner as to be easily cleansed. Demountable apparatus with which “manufactured dairy products” come in contact shall be taken apart and cleansed each day such apparatus is in use. The secretary, upon approval of the design, installation and operation of the system, may permit in-place cleaning. Surfaces with which “manufactured dairy products” come in contact shall be smooth, noncorrosive material and free of open seams.

(h) The milk plants in which “manufactured dairy products” are prepared shall not be constructed or altered until plans and specifications thereof have received the approval of the “secretary.” Equipment before being installed shall likewise be approved by the “secretary.”

(i) “Manufactured dairy products” shall comply with definitions, standards of identity, and labeling requirements adopted hereunder by regulation, and shall not contain any substance not normally found therein, except those substances approved by the “secretary.”